It's a measure of the controversy that the subject of gratuities can generate, that I recently stumbled into a debate on the topic, not on a foodie website, but on a forum for rugby union fans. While having his credit card processed, an individual had been asked whether he would like to leave a tip - something he was understandably irked by. But from there the online debate widened to include myriad irritations about the system of rewarding service.

A prime concern was that if staff were not being paid properly by their employers, why should customers subsidise the owner's meanness by topping up wages? I felt compelled to point out that not all restaurateurs pay as little as they can get away with.

There was also a perception that the amount a person leaves in tips will dictate the standard of service they receive next time.

A third objection was that tipping was somehow humiliating to the staff, who are expected to bow and scrape in the hope that they will be tossed a few extra pennies. My experience is that it doesn't work that way, and the best tips tend to come from customers who are friendly and civil to those serving them.

To return to the original scenario, though, I don't think it's ever acceptable to put customers on the spot as far as tipping is concerned. To do so is embarrassing for the guest and indeed demeaning for staff. The same goes for the habit of adding a "discretionary" 10 or 12% service charge to the bill, which once again forces the customer into a position where they have to make a declaration should they object to paying it.

The restaurant industry would be better off without either of these customs. The great virtue of the majority of tipping in the UK is that it's voluntary and meant to show appreciation of the performance and effort of the staff who receive the cash.

This seems to me a perfectly civilised practice, and one we should seek to uphold.

• Simon Wright's book, Tough Cookies, is out now in paperback, published by Profile, price £7.99.

Valentina Harris, Amici Café, Wandsworth, south-west London
"Absolutely not. If somebody has given particularly good service then they should be rewarded. It really is all about individual cases. I don't personally agree with service charges - tips should be voluntary. It's the one time you're allowed as a customer to state your opinion."

Claude Bosi, chef-owner, Hibiscus, Ludlow, Shropshire
"I don't agree with service charges, because if the customer is paying £40, £50 or even £60 for a meal then it should cover the cost of the service - it's not the customer's fault that the restaurant needs extra waiters. Service charges take people for granted, but tips should be kept - at the customer's discretion."

Oliver Rowe, chef-owner, Konstam at the Prince Albert, King's Cross
"Front-of-house staff often get paid low wages, and then get service charges on top. It depends whether you want it to be automatic or whether you'd rather decide for yourself. I used to not like paying service charges but am getting more used to it. At least tips generally mean the staff get rewarded if they provide good service."

Graham Turner, chief executive officer, Tragus
"We're very much into good service in our business, and tips are a marvellous way of reflecting this. They really are the best way to measure performance in the UK service industry and, problems with tronc legislation aside, there's really no more direct way to show appreciation of good service."